The Social Democrats and chancellor Angela Merkel’s Christian Democratic Party have emerged from Berlin state elections as the strongest two parties – biut it came amid significant gains for the country’s far-right AfD party.

Both main parties lost enough support to ensure they will not be able to continue a coalition government together, according to exit polls on Sunday.

The SPD won 23% of the vote, dropping 5.3%, while the CDU won 18%, down 5.4%, ARD public television reported.

The anti-immigrant nationalist Alternative for Germany party won 11.5% of the vote, behind the Greens and the Left party, each with 16.5%, but with more than enough to enter Berlin’s state parliament, its 10th nationwide.

The vote comes two weeks after Mrs Merkel’s CDU came in third in the eastern state of Mecklenburg-Western Pomerania, and Sunday’s showing – her party’s worst in the capital – will keep up the pressure on the chancellor a year ahead of national elections.